• 경영과학
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• 제21권1호
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• pp.77-86
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• 2004

In this paper, we present a methodology for solving the multicommodity network flow problems using interior point methods. In our method, the minimum cost network flow problem extracted from the given multicommodity network flow problem is solved by primal-dual barrier method in which normal equations are solved partially using preconditioned conjugate gradient method. Based on the solution of the minimum cost network flow problem, a warm-start point is obtained from which Castro's specialized interior point method for multicommodity network flow problem starts. In the computational experiments, the effectiveness of our methodology is shown.

• 산업융합연구
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• 제22권9호
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• pp.17-30
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• 2024

본 연구는 전략적 일탈, 경영자 능력이 경영성과인 영업활동현금흐름에 미치는 영향을 검증하고자 하였다. 또한 전략적 일탈과 영업활동현금흐름의 관계에 경영자 능력이 미치는 영향을 검증하고자 하였다. 표본 선정은 2011년부터 2020년까지 12월 결산상장법인 중에서 비금융업을 대상으로 추출하여 분석하였으며 그 결과는 다음과 같다. 분석 결과, 전략적 일탈은 영업활동현금흐름에 유의적인 음(-)의 영향을 미치는 것으로 확인되었으며 경영자 능력은 영업활동현금흐름에 유의적인 양(+)의 영향을 미치는 것으로 나타났다. 또한 이익조정 수준이 높은 집단에서 이러한 결과를 재확인할 수 있었다. 본 연구는 최근 경영전략과 관련된 연구를 확대하여 영업활동현금흐름에 미치는 영향을 검증한 것에 의미가 있다. 또한 이러한 관계에 경영자 특성을 규명한 것에 의미가 있을 것으로 보인다.

• 지식경영연구
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• 제11권1호
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• pp.129-146
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• 2010

As knowledge has become the most important means of production for a company to survive in a "knowledge-based society", knowledge management has become the key issue in the corporate sector. Despite its growing significance, there are limited numbers of research that describe how companies actually develop, share and practice their knowledge. From this perspective, this study used a qualitative approach to explore on the actual process of knowledge management implementation. In-depth interviews with eleven senior managers, who were working at S global corporation, were conducted. The results show that there are differences between how the participants perceive and how they actually perform in managing knowledge. While the participants tend to conceptualize knowledge management as building a technical system, their performance has shown that knowledge has been developed and shared through active interaction among the members in the company. The factors that impede knowledge management were caused by the individualized job assignment and inapplicable exercises that result in obscuring information flow and utilizing inadequate and low quality of knowledge. The findings of this study imply that knowledge management is not a matter of formality but a paradigm that assures for the flow and share of knowledge.

• 지식경영연구
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• 제10권2호
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• pp.49-63
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• 2009

In this study, sub domain of flow was investigated on literature survey, and suggested of the measuring method of web-site flow and its simulation analysis. Constructing of measuring method of flow, and using this method what-if analysis was simulated when several condition changed. Using causal map approach to extract knowledge from web-site domain experts and to derives a causal relationship of knowledge. Specially, in our study, describes method of developing and building causal map, and suggests guide line of this method on practical application. This research results show that web-site flow starts "direct searching" or "interesting of special issue(domain)", and when challenges of web-site were accorded with user's skills web-site flow grows. Further, in the web-site, information searching intention results in increase of user's duration time and experience flow to discovery new interesting issues in this process. If user's web-site of interaction is increased, awareness of environment conditions decreased, finally, user's telepresense results in increased web-site flow. This paper contained thai this method make used of measuring flow in the web-site and developing of practical strategy.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.82-84
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• 2003

Watershed boundaries and flow paths within the watershed are the most important factors required in watershed analysis. Most often the derivation of watershed boundaries and stream network and flow paths is based on topographical maps but spatial variation of flow direction is not clearly understandable using this method. Water resources projects currently use 1: 50, 000-scale ground survey or aerial photography-based topographical maps to derive watershed boundary and stream network. In basins, where these maps are not available or not accessible it creates a real barrier to watershed geo-spatial analysis. Such situations require the use of global datasets, like GTOPO30. Global data sets like ETOPO5, GTOPO30 are the only data sets, which can be used to derive basin boundaries and stream network and other terrain variations like slope aspects and flow direction and flow accumulation of the watershed in the absence of topographic maps. Approximately 1-km grid-based GTOPO 30 data sets can derive better outputs for larger basins, but they fail in flat areas like the Karkheh basin in Iran and the Amudarya in Uzbekistan. A new window in geo-spatial hydrology has opened after the launching of the space-borne satellite stereo pair of the Terra ASTER sensor. ASTER data sets are available at very low cost for most areas of the world and global coverage is expected within the next four years. The DEM generated from ASTER data has a reasonably good accuracy, which can be used effectively for hydrology application, even in small basins. This paper demonstrates the use of stereo pairs in the generation of ASTER DEMs, the application of ASTER DEM for watershed boundary delineation, sub-watershed delineation and explores the possibility of understanding the drainage flow paths in irrigation command areas. All the ASTER derived products were compared with GTOPO and 1:50,000-based topographic map products and this comparison showed that ASTER stereo pairs can derive very good data sets for all the basins with good spatial variation, which are equal in quality to 1:50,000 scale maps-based products.

• 센서학회지
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• 제13권2호
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• pp.79-84
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• 2004

Asthma is one of the important respiratory diseases requiring home self care usually performed by commercialized peak expiratory flow meter (PEFM). However, this simple device can measure only single parameter, PEF, due to its purely mechanical principle, significantly limiting desease management quality. The present study introduced a new expiratory flow measurement technique by miniatured air expansion chamber easily installed within PEFM. Continuous pressure signal obtained from the chamber demonstrated an accurate quadratic relationship with flow. The volume measurement error was $<{\pm}1%$ well within the American Thoracic Society (ATS) criteria of 3%. Important spirometric parameters of FVC, PEF, and FEF25-75% were all accurately estimated with correlation coefficients > 0.95. The present technique obtains continuous expiratory air flow signal, making possible and convenient to perform spirometric test at home. Electronic interface capability would be also useful for remote asthma management.

• Management Science and Financial Engineering
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• 제3권1호
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• pp.15-38
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• 1997

In a flexible manufacturing system, a cell controller is able to identify and evaluate a number of alternative decisions to meet the objectives set by the factory level controller. In this paper, a Petri net-based cell controller is presented to accomplish this task. A static model is developed by using the Integrated Computer Aided Definition(IDEF0) method to represent clear functional relationships among the objects of the system. Based on the static model, two Petri net models are developed for the physical part flow and for the information flow. Multiple decision alternatives are generated from the physical part flow model and are synchronized with the information flow model for execution of the selected alternative.

• Spatial Information Research
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• 제8권1호
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• pp.131-140
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• 2000

하천의 흐름해석 분야에서는 모형이 요구하는 입·출력 자료의 구성이 복잡할 뿐만 아니라 흐름의 공간적 분포특성 도시가 매우 중요하지만 지금까지 체계적인 자료관리가 이루어지지 않은 실정이다. 본 연구에서는 등고, 하천, 표고, 경계 및 하도단면 등으로 구성된 국가지리정보시스템과 연계된 데이터베이스를 구축하는 방법과 등간격 하도단면 자료를 구축하는 방법을 제안하였다. 연구대상지역은 팔당댐 하류에서 인도교 지점에 이르는 한강구간을 선택하였다. 구축된 데이터베이스는 연구대상지역의 과학적인 하천유량 관리에 유용하게 이용될 것이다.

• Journal of Communications and Networks
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• 제15권2호
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• pp.207-216
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• 2013

Vehicular ad-hoc networks (VANETs) are self-organizing, self-healing networks which provide wireless communication among vehicular and roadside devices. Applications in such networks can take advantage of the use of simultaneous connections, thereby maximizing the throughput and lowering latency. In order to take advantage of all radio interfaces of the vehicle and to provide good quality of service for vehicular applications, we developed a seamless flow mobility management architecture based on vehicular network application classes with network-based mobility management. Our goal is to minimize the time of flow connection exchange in order to comply with the minimum requirements of vehicular application classes, as well as to maximize their throughput. Network simulator (NS-3) simulations were performed to analyse the behaviour of our architecture by comparing it with other three scenarios. As a result of this work, we observed that the proposed architecture presented a low handover time, with lower packet loss and lower delay.

• 경영과학
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• 제27권3호
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• pp.117-135
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• 2010

The purpose of this study is to segment the mobile phone users based on the flow types and to understand the differences in mobile phone usage behavior between the segmented groups. The 'flow' construct, which was introduced first in marketing by Hoffman and Novak[44], has been used as an important keyword for understanding consumer behavior on the World Wide Web. In this paper, we will try to use the flow aspect for the mobile market segmentation, which is one of the most fundamental tools for developing a successful marketing strategy on the mobile phone service market. We collected survey data from consumers and analyzed the data with the SPSS 12.0 package where we did ${\chi}^2$-test, factor analysis, one-way ANOVA and cluster analysis. Main results of this study are as follow. First, the flow types of the mobile phone users were classified into five types, which are named as the 'Flow' type, 'Apathy' type, 'Anxiety' type, 'Boredom' type, 'Control' type. Second, most of the results related to the usage of mobile phone service showed statistically significant differences between flow types. These findings suggest that the mobile phone service marketers should consider the various flow types of users and work out effective market segmentation strategies based on these consumer flow types.